Feeding mechanism for sewing machines



Jan. 8, 1935. KNAUS 1,987,196

FEEDING MECHANISM FOR SEWING MACHINES Filed Sept. 19, 1933 I 2 Sheets-Sheet 1 Mme 'Jan. 8, 1935. N. KNAUS FEEDING MECHANISM FOR SEWING MACHINES 2 Sheets$heet 2 Filed Sept. 19, 1933 3mm Mcizolaus Knaus Patented Jan. 8, 1935 UNIT Ni J;', a', corporation of New Jersey Ap li ationfiept m f 1 93 l N?- 690,061

; 4Claims.i(Cl'. 1'12-20 9) V This invention relates. to improvements in sewing machines, and more particularly to a feeding mechanism embodying two feed-dogs 'whi'chdare givenv differential movements relative .to each "'5 other. I

In the drawings: 1 x x Figure I is a view part1y'in"plan and partly in section,showing a machine having my improved feed-adjusting mechanism 1 embodied therein.

Figure -:2 is a sectional 'view" takenalongthe line. 2+2 of Figure 1.' a

Figure 3' is a rear elevation of a 'portion of a sewing machine' having my improved feed-adjustingv' mechanism embodied therein;

Figure 4is'aiperspective-viewof the feed-adjusting.mechanism.- 1: x U

My improved feed-adjusting mechanism is shownapplied fto anioverseaming machine such as that disclosed in the patent to A. Grieb, No. 933,033, dated August 31, 1909, and in my copending application Serial No. 639,976, filed October 28, 1932. In the embodiment shown, 1

is the bed of the machine having suitable bearings in which are journaled a. main-shaft 2, p

' frame to vary the throw of the main feed-bar.

and rearwardly extending bearing supports 3 formed with suitable bearing apertures to ceive the feed-rock shaft 4.

Fixed upon the feed rock-shaft 4 is the feedrocker 5 having two spaced lateral arms 6 and '7, each arm having an apertured end which receives a pivot-pin 8. The feed-rocker b receives an oscillatory movement from themainshaft by' means of a pitman 9 having one of its ends embracing an adjustable eccentric 10 on the main-shaft 2, and its other end connected by a pivot-pin 11 to the depending arm 12 which has its split-hub 13 secured to the feed-rocker 5.

Disposed intermediate the arms 6 and 7 of the feed-rocker and carried by the pivot-pin 8 is the enlarged apertured end 14 of the auxiliary feed-bar 15 which carries on its forwardly projecting end 16 the auxiliary feed-dog 17. A main feed-bar 18 is slidably carried on the auxiliary feed-bar 15, the main feed-bar being provided with a rib 19 which enters the channel 20 in the auxiliary feed-bar and a longitudinal aperture 21 which receives the stud 22 carried by the auxiliary feed-bar. The above described connection permits the main feed-bar to be reciprocated on the auxiliary feed-barand independently thereof, but connected thereto, so as to be moved up and down therewith. The forward end of the main feed-bar carries a main feed-dog 23 which is located in rear of and substantiallyin' alignment with the auxiliary feed-dog 17.

The auxiliary feed-bar 15 overhangs the usual feed-lift eccentric r24 on the main-shaft;-and a" short pitman 25 "embracingfthe nfeed-lift :ecs centric is pivotally connected touthe bar 15 by means of a pivot stud 26 carried by the pitman. Through this connectionwith the main-shaft, the feed-bars receive their rising andrfalling movement. The above rdescribed differential. feeding mechanism issubstantially the same. as that forming the subject'of my copendingqapplie cation Serial No. 639,976,'fi1ed' October 28,; 1932-, to which reference'may be had'forra more-de'jtaileddescript'ion. T I i Inorder to varythethrow of the mainifeeddog relative to the auxiliary feed-dogWI have connected thelmain feed-bar. to ansadl'u sliding member 2'lby means of a link 28:2. 'I'hefadv justabieusliding member is' provided withg-arnslpt 29 and a rearwardly projecting hand piece 30. The walls of the slot 29 slidably engage a boss 31 carried by the arml'l of the rocking frame 5 so that the pivotal connection between the main feed-bar and the rocking frame may be shifted relative to the axis of oscillation of the rocking To look the adjustable member 27 in any'desired position the rearwardly projecting handpiece 30 has a locking-dog 32 pivoted thereto by means of. the pivot-screw 33. The locking-dog 32 is formed with a toothed portion 34 which co-acts with the toothed section 35 formed on the retaining plate 36 which is fixed by the screw 37 to the boss 31 and arm '7. A compression spring 38 reacts between the hand-piece 30 andthe locking-dog 32'and tends to constantly urge the locking-dog into engagement with the toothed section 35. It will be observed from the forego ing that the hand-piece so and locking-dog 32 I are located in rear of the machine so that they may be readily grasped by the operator, and the sliding member 27 shifted to any desired position. This construction is compact, rugged, and easily and quickly operated. It will also be observed that the plate 36 serves a double purpose, first against turning once it has been set at the desired position. A stop-plate 41 is adjustably secured to the arm '7 by means of a screw 42 which extendsthrough the slot 43 intheplate 41 and is threaded into the arm 7 of the rocking frame 5. From the foregoing it will be obvious that the screw 39 may be adjusted to. limit thedownward movement of the sliding member 27- and that the plate 41 maybe adjusted to a position which will limit the upward movement of the member; 2'7.

Having thus set forth the nature of the invention, what I claim herein is:-

1. In a difierential feeding mechanism forsewing machines, a feed-rocker including an arm having a boss projecting from-one side ihereof, said boss presenting surfaces'which arei.- spaced from one another, an adjustable member formed with a slot the walls of which slidably engage said surfaces, said adjustable member having 1 operated. by said lfeederockerz and'said' adjustable mergimdnmeans for raising: and lowering said teeddaarsp 112.11. xa-z'difierential feeding mechanism for'sew- 'lngszmachines, *a f eed-"rock'er including? an :7 arm havmgrzaibossiprojectmg from one side thereof,

member'i in its :adjusted I positionpan adjustable stop to limit the upward movement of said slidable member, a second adjustable stop to limit the downward movement of said slidable member,

main and auxiliary teed-bars connected to be op- I erated by said feed-rocker and said slidable memw her, and means for raising and lowering said feed-bars. "3. A feeding: mechanism tor-sewing machines including in combination, a' feed-r'ocker having spaced arms, an auxiliary feed-bar pivoted be- "tween said arms, means for raising and lowering vtsaid,fieed-ibar, ar'main feed-bar slidably carried :onsaid auxiliary feed-bar, a boss carried by one of, said arms, an adjustable member formed with ebosassaid-sliding member having a rearwardly.

projecting hand-piece, a locking member carried bysaitihancbpiecey'aplate with which said lock- .iingwmember cooperates to lock the adjustable member in its desired position, and a link pivotally-rcunnecting :saldimainifeed-bar :with: said a'zdjustablexmember. j

Ina-differential feeding, ing: machines, r13 feederocker including nan" :am having a boss projecting from one side thereof, an adjustable member form-dflwithiasslotxthe walls 10f i'which siidabl'y engage isaid: boss, agiplate secnredatogsaid' boss; formetaining said adjnstable' member; ton ,wboss, 12a; rearwardl'y extending :handrpi'ece onsaid adjustable anemben: a lockingdog pivotally secured to said h|nd=piece;-andaco- Ioperatingmirh sematinnszcnwsaidplate @Of'ilObkechanismi ing saidradaustable in itssdesiredposition,

main and muxilziaryz-iteedsbars connectedrzlto'z be operated saidztecdemckenrmdsaidfiadiustable member, and means for ieedebars.

f I iimcnomuswxnans. a

raisingrandlowerin'g. 

